In the case of wind turbine rotor blades having a so-called thick trailing edge, the trailing edge of the rotor blade is, in contrast to a thinly tapering profile, formed not by a line but rather by a rear surface. If the rotor blade is viewed in cross section, that is to say in profile, the pressure side and suction side do not merge at a point at their rear edges, but rather the rear ends of the pressure and suction sides have a spacing to one another, which is bridged by a surface substantially perpendicular to the profile chord. From an aerodynamic aspect, a thinly tapering trailing edge is generally advantageous because the air flowing past the pressure side and suction side can flow smoothly off the trailing edge without any relatively intense turbulence necessarily occurring. In the past, it has therefore been sought to design the trailing edges of rotor blades to be as thin as possible, wherein a manufacturing limit lies in the range of approximately 1 mm to 3 mm.
It has, however, been found that the use of relatively thick trailing edges can be advantageous in particular from a structural aspect in the blade root region. It is thus possible to design the rotor blade to be more lightweight and to nevertheless realize a profile height required from a strength aspect. In the case of rotor blades for large wind turbines, it is today common to use aerodynamic profiles with thick trailing edges in a region close to the blade root. The aerodynamic performance of such profiles also has its benefits, in particular a higher lift coefficient, a steeper gradient of the lift curve and lower sensitivity of the lift coefficient, to the accumulation of dirt on the profile leading edge, in each case in relation to a profile with a thin trailing edge and identical profile thickness.
Known disadvantages of profiles with a thick trailing edge are however a greater flow resistance and more intense noise generation.
U.S. Pat. No. 7,585,157 discloses a rotor blade for a wind, turbine wherein an areal element which is oriented substantially in the flow direction projects from the suction side. The areal element is intended to counteract a transverse flow running from the blade root to the blade tip.
Publication KR 20100079522 A discloses a wind turbine rotor blade wherein it is sought to counteract a radial flow of the air along a surface of the rotor blade. The known rotor blade has a blade root section of circular cross section and an adjoining blade tip section. To prevent the radial flow, a partition wall is arranged on the pressure side between the blade root section and the blade tip section.
U.S. Pat. No. 7,918,653 discloses a wind turbine rotor blade having a rotor blade trailing edge assembly. To reduce the trailing edge noise, the thin trailing edge is terminated in a varied manner, for example using teeth of triangular form or bristles.